Utah & Idaho Bill Proration for Seasonal Changes

Each year as you move from winter to summer months and later from summer to winter months, your bill will show your current seasonal electric rate (energy charge). If the service period reflected on your bill includes days from both summer and winter billing rate periods, your bill is prorated. The calculation is made by prorating your usage according to the number of days in the billing period during the transitional months (April to May and September to October).

Summer rates are in effect May 1 through September 30 and are billed on a 3-block schedule referred to as Energy Charge Summer Block 1 (1-400 kwh), Energy Charge Summer Block 2 (401-1000 kwh) and Energy Charge Summer Block 3 (over 1000 kwh) for a 30 day service period. Each of the Summer Blocks has a different charge, the more you use, the higher the charge. The rate encourages conservation during the months when electricity usage is at its peak in the Summer. Winter rates are in effect October 1 through April 30 and are billed in two blocks: Block 1 (1-400 kwh) and Block 2 (over 400 kwh).

The amount of kwh you are billed in each of the Summer Blocks is prorated according to the number of days in the billing period within each season. Please see the sample bill below for information on how to better understand your seasonal prorated bill (this is a sample bill, actual details will vary):

If you would like to calculate how your bill is prorated when transitioning from winter to summer months and summer to winter months, you can use these proration formulas to allocate kwhs from summer to winter and winter to summer months:

Step 1: Calculate the per day kwh average

Take the total number of kwh (Amount Used This Month) and divide by the number of days in the billing cycle (Elapsed Days). This will give you the per day kwh average.

Step 2: Determine how many days should be billed on the winter rate, and how many days should be billed on the summer rate.

Your billing statement tells you how many days are in the billing period (Elasped Days) and the dates for the start and end of the billing period (Service Period). In the billing example above the Service Period begins April 27 and ends May 26 making 3 days in April and 26 days in May. The number of days is also included in the Energy Charge description line on the billing statement. To determine how many days should be billed on the winter rate take the per day average from Step 1 and multiply by the number of days the winter rate is in effect. This will give you the total number of kwh to be billed on the winter rate. You can also take the average from Step 1 and multiply by the number of days the summer rate is in effect. This will give you the total number of kwh to be billed on the summer rate.

Determine how many kwh to bill on Summer blocks 1, 2 & 3

Step 3: Determine how many kwh to bill on Block 1

Take 400 and divide by the number of days in the billing cycle (elapsed days). This will give you the first block per day average. Multiply this number by the number of days the summer rate was in effect. This will give you the maximum number of kwh to be billed on the first block.

*Please note – If your summer kwh usage does not exceed the maximum number of kwh allowed for summer block 1, you will have no kwh usage on summer blocks 2 and 3.

Step 4: Determine how many kwh to bill on Block 2

Take 600 and divide by the number of days in the billing cycle. This will give you the second block per day average. Multiply this number by the number of days the summer rate was in effect. This will give you the maximum number of kwh to be billed on the second block.

*Please note – If your summer kwh usage does not exceed the maximum number of kwh allowed for summer block 2, you will have no kwh usage on summer block 3.

Step 5: Determine how many kwh to bill on Block 3

Any remaining kwh to be billed on the summer rate will be billed on the third block. You will not be billed more than the total number of kwh to be billed on the summer rate under step 1.

Determine how many kwh to bill on Winter blocks 1 & 2

Step 6: Calculate the per day kwh average

Take the total number of kwh (Amount Used This Month) and divide by the number of days in the billing cycle (Elapsed Days). This will give you the per day kwh average.

Step 7: Determine how many days should be billed on the winter rate, and how many days should be billed on the summer rate.

Your billing statement tells you how many days are in the billing period (Elasped Days) and the dates for the start and end of the billing period (Service Period). In the billing example above the Service Period begins April 27 and ends May 26 making 3 days in April and 26 days in May. The number of days is also included in the Energy Charge description line on the billing statement. To determine how many days should be billed on the winter rate take the per day average from Step 6 and multiply by the number of days the winter rate is in effect. This will give you the total number of kwh to be billed on the winter rate. You can also take the average from Step 6 and multiply by the number of days the summer rate is in effect. This will give you the total number of kwh to be billed on the summer rate.

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